Niemann-Pick disease Type C (NPC) is a lysosomal lipid storage disorder caused by autosomal recessive mutations in either the NPC1 or NPC2 gene. Symptoms typically manifest beginning in the perinatal period and progress throughout life. The disorder often includes neurological symptoms, such as cerebellar ataxia, dysarthria, seizures, vertical gaze palsy, motor impairment, dysphagia, psychotic episodes, and progressive dementia, as well as systemic symptoms in other organs, such as the liver, spleen, or lung. NPC has been described as a cellular cholesterol transport defect, although in the brain accumulation of other lipids, such as GM2 and GM3 gangliosides, also occurs (Vanier, 2010, Orphanet Journal of Rare Diseases, vol. 5: 16). Owing to different clinical presentations and course of disease, NPC1 disease is typically categorized as early-infantile onset (<2 yrs), late-infantile onset (2 to <6 years), juvenile onset (6 to <15 years), and adolescent/adult onset (>15 years).
Efforts to treat NPC in humans have focused on substrate reduction therapy, such as inhibiting glycosphingolipid synthesis, for example with N-butyldeoxynojirimycin (miglustat, Zavesca®), or on ameliorating overall lipid storage, particularly storage of cholesterol and glycosphingolipids, through clearance mechanisms.
2-Hydroxypropyl-beta-cyclodextrins have been shown to alleviate excess cholesterol storage in NPC cells (Abi-Mosleh, L. et al., Proceedings of the National Academy of Sciences USA, 2009, vol. 106 (46), pages 19316-19321), consistent with a previous report of related cyclodextrins extracting cholesterol from the plasma membrane of cells (Rodal, S. K. et al., 1999, Molecular Biology of the Cell, vol. 10, pages 961-974). Hydroxypropyl beta-cyclodextrins have also been observed to have beneficial effects in animal models of NPC. For example, a composition comprising 2-hydroxypropyl-beta-cyclodextrins was reported to reverse defective lysosomal transport of cholesterol in the liver and brains of Npc1 knockout mice, and led to a prolongation of life in these mutants compared with no treatment (Liu, B. et al., 2009, Proceedings of the National Academy of Sciences USA, vol. 106 (7), pages 2377-2382; Davidson et al., 2009, PLoS One 4:e6951).
Various hydroxypropyl beta-cyclodextrin compositions have been administered to human NPC patients in the United States, Brazil, and Japan under compassionate use exemptions, with anecdotal reports of some improvement in various signs and symptoms. However, blinded clinical trials of hydroxypropyl beta-cyclodextrin compositions to determine safety and efficacy have not been completed (Ottinger, E. A. et al., 2014, Current Topics in Medicinal Chemistry, vol. 14 (3), pages 330-339). Given likely observer bias in the anecdotal reports, there is a need for controlled clinical studies to confirm that hydroxypropyl beta-cyclodextrin provides clinical benefit.
Effective treatment of NPC will require chronic intrathecal or intracerebroventricular administration beginning in infancy, and parenteral grade compositions of hydroxypropyl beta-cyclodextrins used previously in human patients contain impurities that make them unsuitable for chronic administration directly to the cerebrospinal fluid of infants and children: propylene glycol, which is thought to be ototoxic; beta-cyclodextrin molecules having no hydroxypropyl substitutions, which are known to form precipitates and to have an acute toxicity (Muller and Brauns, 1985, International Journal of Pharmaceutics, vol. 26, pages 77-88); and bacterial endotoxin, which is highly inflammatory. There is, therefore, a need for pharmaceutical compositions of hydroxypropyl beta-cyclodextrins of higher purity.
In addition, all existing parenteral grade compositions of hydroxypropyl beta-cyclodextrins contain complex mixtures of hydroxypropyl beta-cyclodextrin species having different degrees of hydroxypropyl substitution. The ratios of these species within the mixture differ widely among the various suppliers, and vary even among batches from a single supplier. It is not known how these different species contribute to the pharmacological effects of the complex mixture. There is, therefore, a need for pharmaceutical compositions of hydroxypropyl beta-cyclodextrins having more precisely defined and precisely controlled mixtures, or fingerprints, of such species.
There is, finally, a need for methods of manufacturing at commercial scale under GMP conditions pharmaceutical compositions of hydroxypropyl beta-cyclodextrins suitable for chronic intrathecal or intracerebroventricular administration, having low levels of impurities, and having specific and structurally-defined composition.